The ability of cells to sense and respond to the mechanical stiffness of the surrounding matrix is important to support normal cell function, wound healing, and development. Central to the process of durosensing is the cytoskeleton composed of three classes of filaments: F-actin, microtubules, and intermediate filaments (IFs). Vimentin is an IF protein that contributes significantly to cell mechanics and cell traction force, which is required to probe extracellular matrix. The role of vimentin in how cells sense and respond to the mechanical rigidity of extracellular matrix is largely unclear. To investigate the role of vimentin in durosensing, we knocked down the vimentin expression level in 3T3 fibroblasts using shRNA transfection and measured cellular responses as functions of substrate stiffness. We quantified durosensitivity by the rates at which cell area and traction force change with substrate stiffness. Our results show that that vimentin plays a role in durosensing by modulating traction force and knocking out vimentin did not significantly affect durosensitivity. These results indicate that vimentin may be a redundant component of the machinery that cells use to sense substrate stiffness.

中文翻译：

---

波形蛋白中间丝调节细胞牵引力，但不调节细胞对底物刚度的敏感性

细胞感知和响应周围基质的机械刚度的能力对于支持正常的细胞功能、伤口愈合和发育很重要。核心传感过程的核心是由三类细丝组成的细胞骨架：F-肌动蛋白、微管和中间细丝 (IFs)。Vimentin 是一种 IF 蛋白，对细胞力学和细胞牵引力有显着贡献，这是探测细胞外基质所必需的。波形蛋白在细胞如何感知和响应细胞外基质的机械刚性中的作用在很大程度上尚不清楚。为了研究波形蛋白在durosensing 中的作用，我们使用shRNA 转染降低了3T3 成纤维细胞中波形蛋白的表达水平，并测量了细胞反应作为底物硬度的函数。我们通过细胞面积和牵引力随基板刚度的变化率来量化硬脑膜敏感性。我们的研究结果表明，波形蛋白通过调节牵引力在硬脑膜敏感中发挥作用，敲除波形蛋白并没有显着影响硬脑膜敏感性。这些结果表明波形蛋白可能是细胞用来感知底物硬度的机制的冗余组件。